Push button switch with double switch mechanism



Dec. 17, 1957 F. A. HARRINGTON ETAL 2,816,995

PUSH BUTTON swTTH wTTH DOUBLE sw'TTcH MEcHANTsM v Filed Aprila, 195e 29 C a9 6 INVEN ToRs:

2 FRA/vl( AHARe//vcTOA/a THOMAS W JENTGES.

A T TOPNEY.

United States Patent() PUSH BUTTON SWU" CH WlTH DOUBLESWITCH MECHANISMA FrankA; Harrington," Brea, andThomas W. `ientges,

Santa Ana, Calif., assignors to Marco Industries Com- I ipany, Anaheim, Calif., a corporation of California Application April 3, 1956, serial No. 575,737

11 Claims.` (ci. zoog-167)" This inventionrela-testo electric switches of thepush- 15 button type and-has as its `general object tovprovide 4a switch embodying'an'illuminated push button.

Thergeneral object of-the invention -is to provide a pushbutton switch having a novel and'imp-roved switch unitarranged to beactuated by rearward-movementgdn 21:20 mounting barrel, of a lamp-holdin'g-tube that is slidably mounted in the barrel, Vthe forward end-of 'the tube being f' provided with-a push-buttonhead having-a lensor lightaperture through which the raysof the lampwithin-the tube, will-shine to illuminate suchl head.

Morespeciiically, the invention contemplatesv such a switchrembodying a fixed assemblyof'- four terminalsv in its rrear end, two of the terminals providing connections` tothe lamp -forilluminating the same, and the other two'y terminals providing connections from said switch -unit toy a circuit thatis entirely separate fromthe lamp circuit,l and maybe wholly isolated-therefrom,l electrically'.

In particular, the invention contemplates a xed assemblyof` terminaly .rings Vor Vequivalenthparts disposed-` radially and axiallyspaced by'insulator means lsuch as 35 a succession of discs sandwiched-between the-'rings,'theJl rings rbeing integral with terminals that projectfrom the rear end ofthe barrel for connectionuto circuits'including alamp energizing circuit' and anl external= circuit;J and i" wherein the switch unit comprises a springurged plungerlslidably mounted in onel -of thev'termi-nalV rings at` its periphery andmovable -intoengagement witlfrianotherV of-i the'termi-nal rings-when the head ispushed'. One-of the terminals is connected-'t0 a center-contact of-the 'lamp/F through `a sliding pinlthat extendsfthrough the-'termin-ali'fl ringsat their axis and is insulated therefrom.

Irithe preferred form'lof'the invention; a fourth terminal, constitutingan axialiextension of the la'mp housing:i tube, isprovidedwith'a radially inwardly-extendingstop# finger which engages an insulator disc rto-determine the-r normal, lretracted positionof the-lamp housing-tube; Inf modified-forms yof theinvent-ion, such -`finger fu'nctionsasZ L a supplementary `movable switch contact to engager-one? of the terminal ranges."

A-'specific object is toprovidea double throw switch-i 55 havinglfa -pair of normallyvl closed 'contactsV which are opened when the push button is pressed andy havin'gra pair of',normallyoperrlcontacts which are -closed whenf the push "button iswpressed TheA inventionfurtherl con templatessuch a switch;y adapted to` be connected to lex-l ternalrcireuits `indifferent arrangements suchthat either its'normally open -or==its normallyv closedrswitch'contactsy1 may be utilized towcarryelectric currentto "an illuminatI ingslamp -behi-'ndf the `switchbutton, whereby the but-ton# maybe normally illuminated and darkened when pressed, 05 orpin the= alternative, may be normally'v dark andillumiff nated `when.presseclpdepending upon-the speciiications'; of` a particular` installation. t

The invent-ionfurther contemplatessuch -a yswitch that` will provide `forthree alternative selections, namely),= `the-Y normally illuminated push button and/the `normali-y fda'rlc'? gash button,` both :referred to `above;4 and,` z asiv a nfutther alternative,a constantly illuminated push button remaining illuminatedin both of the alternative positions `of-theA switching mechanism, with the two pairs of switch contacts beingV available to control two external circuits. Thus, the inventionprovides for the possibility of three separate v'circuits including the internal button'illumnan ing circuit and two separate external circuits, both switchcontrolled and oneV normally energized and the other normallyopen.

The invention'v further aims to provide such a switch wherein a common' connection from an external circuit element (e`` g. a source-of'electric current) services both the normally openand the normally closed switch.

Other objects will become apparent in the specificationsy andappended f drawings in which:

Figure -1 is a side elevational view, partially in section, of-a push-button switch embodying my invention;

Figure 2 'is a `longitudinal sectional view thereof taken on thef1in`ev2`2 of IFigure l;

Figure 3 is a transverse sectional -view taken on the line V3--3 of'rFig'ure 2;

Figure-4 is a terminal-end view of-the switch;

Figures 5,'6 and-S17 are pneumaticv wiring diagrams showing variouscir'cuit arrangements to which the switch i' can Ibe-adapted; r`and Figs, 8 and-9 show -a modified form of the invention.l

Referring now tothe drawings in detail, therel is shown, asl-an example jofone lform in whichthe Vinvention may belembodied, an illuminated push-button switch, including jv ingeneral, a barrel assembly A, a lamp casing-and head uni-t B,`fand va terminaland contact assembly C.

Barrel assembly A may Y embody a cylindrical" barrel 10 having an external thread 11 and an assembly of mount-f inglnuts and-washers `12 thereon; also, a lining tube-'13` of insulating material. 1

Lampcasing and head unit Brincludes la lamp casing tube 14 having an extension 1S telescoped.th'ereonand` insulatedl therefrom as indicated', a Apush-button 'head' assembly 16 being attached to therouter end of-extension' 15 Tand-having a` transparent or-translucent lensr17 for transmitting illumination from va lamp 18 mounted within casing tube-r14s-v Merely asv an illustration of-'onepossible method of mounting thelamp, I have showna known' arrangement wherein thelbase capsule 19"of 'the'ilamp-j is seatedagainst a washer 20 which, in turn, is' seated on a coil-spring 21 bearing against an inwardly extendingr radialdange 22 atthel rear end of tube l14,'the forward' end of lamp `18 being seated againsthead 16, as shown. i

Mountedin the rear end of barrel- 10 is the terminal 1' and` Contact assembly C, comprising a sandwich arrange-'- ment of insulating-discs 23, 24 and-25 anda series of metal'rings 26, 27 and28, each of said rings constituting` one arm of'an--Lpshapedderminal including a second arm" projecting axially through the rear end of the -barrel' assembly A, the three terminal arms being numbered 1, 2 Vand-3 respectively.- Terminal arm-1 extends through Y' registering slots--indiscs -24 and v25,1fas shown;terminal arm-2 extends'through a slot inA therdisc 25, as shown,- and terminal-3 is Ydisposed externally ofzdisc 25. Disc' 2S constitutesl a rear end-cover fo'r vbarrel-10.

Terminalringsflzti and 27"are internallyinsulated'byr small 'insulatorwashers 32 and 33 from the central fbush ing portion of a grommet 34, which extends throughfithe assembly'f'ofdiscs` 23",' 24,925 andi-ings 26,1527 and 28,

contact 661 of lamp 18.

La1np1base, 19 is. electrically rconnected, `through casingf' 3 tube 14, with a fourth terminal 4 (Figure l) constituting an integral extension of casing tube 14 and projecting axially from one side thereof. At this point, it may be noted that terminal 4 is diametrically opposite terminal 3 and terminals 1 and 2 are diametrically opposite one another.

Insulator disc 24 has a peripheral lradial notch 37 in which is received a radially inwardly projecting contact finger 38 on terminal 4. Terminal ring 26.hasa coacting radially outwardly projecting contact finger 39 against which contact finger 38 is normally engaged, as shown in Figure l.

. Contact ring 26 has a second radially projecting finger 40, disposed 90 around its circumference from contact linger 39. Finger 40 has a cylindrical aperture in which is slidably mounted a small switching plunger 41 having a contact head 42 normally engaged against the underside of finger 40 -under the yielding load of a coil spring 43 which encircles plunger 41 and is engaged Vunder compression between finger 40 and a head 44 at the inner end of plunger 41. Spring 43 is accommodated in a notch 30 in disc 23. Contact head is accommodated in aperipheral notch 29 in disc 24.

Interposed between plunger head44 and the rear end of lamp housing tube 14 is an insulator washer 45. Washer 45 may be cemented to ange 22 or may simply rest loosely between the fiange and the contact assembly C.

Lamp housing tube 14 is slidable axially within insulator lining 13 of barrel 10, from the normal position shown in the drawing to a position wherein plunger contact 42' is engaged against terminal ring 27 of terminal 2. The normal retracted position is provided for by a barrel spring 46 engaged under compression between the head of contact pin 35 and the inner head of grommet 34. Pressure against the head 16' of sliding unit B (i. e., against lens 17) is effective to move the housing tube 14.inwardly, compression spring 21, the insulator washer 45 engaging the head 44 of plunger 41 and shifting the plunger 41 to the point where contact head 42 thereof engages terminal 27.

Referring now to Figure 5, illustrating one possible circuit arrangement embodying this improved switch, it will be noted that one side of lamp 18 is permanently connected through sliding contact pin 35 with terminal 3, whereas the other side, through base 19, washer 20 and housing tube 14, is permanently connected to terminal 4, Thus, it becomes possible, if desired, to connect terminals 3 and 4 to a circuit, indicated at H, for constantly'energizing lamp 18 if desired. A second circuit, indicated at I, may be connected to terminals 1 and 4, normally connected through contacts 38 and 39. A third circuit, indicated at I, may be connected across terminals 1 and 2. It will now be apparent that circuit I is a normally` closed circuit and is opened when the pushbutton ,head is pressed; whereasV circuit J is a normally open circuit and is closed when the push-button head is pressed.

Figure 6 illustrates an alternative arrangement, wherein the lamp energizing circuit K is connected across terminals 1 and 3 and is opened when the push-button head isk pressed. Circuit I mayV be the same as in Figure 5, being a normally open circuit which is closed when the push-button head is pressed. Such an arrangement provides for normal illumination of the push button, with the button going dark when pushed to close an external circuit.

Referring now to Fig. 8, there is shown therein a preferred form of the invention wherein the switch 41, 42, Z7 is completely isolated from the lamp circuit, and the lamp circuit is constantly energized. This form of the invention.V differs from the form shown in Figs. 1-3 in that thercontact lug 39 is omitted from terminal ring 26 and the; finger 38 of terminal 4 functions as a stop finger, normally engaging insulator disc 23 to determine the ngrmal, retractedposition of the lamp housing assembly B.

Referring to Fig. 9, showing the electrical diagram for Fig. 8, it will be noted that the lamp energizing circuit H, including terminals 3 and 4, is completely isolated from the external circuit J which is closed when the lamp housing assembly B is pushed rearwardly.

Figure 7 illustrates a further possible arrangement utilizing the structure of Fig. 8, wherein the lamp 18 is normally dark. In this case, the normally open lamp energizing circuit, indicated at L, utilizes the connections 1, 4, and 2, 3, the latter terminals being connected by a jumper 47.

We claim:

l. In an illuminated push-button switch unit: a barrel having means for attachment thereof to a support; a lamp casing tube mounted for axially sliding movement in. said barrel, said tube having a projecting forward end provided with a push-button head having a light transmitting window and having means for mounting an electric lamp therewithin; first, second and third terminals projecting axially from the rear end of said barrel, said first and second terminals each having at its inner end a part disposed in a radial plane, the second terminal part being disposed rearwardly of the first terminal part, insulator means secured in said rear end of the barrel and mounting said first, second and third terminals; a conductor pin slidable in said insulator means and having its forward end in engagement with a central end contact of said lamp; means yieldingly urging said conductor pin forwardly to maintain said engagement; a contact plunger mounted for axially sliding movement in said first terminal part; a spring acting between said plunger and tube and said first terminal part to normally retract said plunger forwardly; said plunger being arranged to receive rearward movement from said tube in response to pressure against said push-button head and being arranged, upon such rearward movement, to establish circuit-closing engagement with the second terminal part, said conductor pin establishing an electrical connection between said lamp end contact and the third terminal.

2. A switch unit as defined in claim l, including a bearing washer of insulating material attached to the rear end of said lamp casing tube, for transmission of movement to said contact plunger.

3. In an illuminated push-button switch: a barrel having means for attachment thereof to a support; a lamp casing tube mounted for axially sliding movement in said barrel, said tube having a projecting forward end provided with a push-button head having a light transmitting window and having means for mounting an electric lamp therewithin; first, second, third and fourth terminals projecting axially from the rear end of said barrel, said first and second terminals each having at its inner end a part disposed in a radial plane, the second terminal part being disposed rearwardly of the first terminal part, insulator means secured in said rear end of the barrel and mounting said first, second and third terminals; a conductor pin slidable in said insulator means and having its forward end in engagement with a central end contact of said lamp; means yieldingly urging said conductor pin forwardly to maintain said engagement; a contact plunger mounted for axially sliding movement in said rst terminal part; a spring acting between said plunger and said first terminal part to normally retract said plunger forwardly; said plunger being arranged to receive rearward movement from said tube in response to pressure against said push-button head, and being arranged, upon such rearward movement, to establish circuit-closing engagement with the second terminal part, said conductor pin establishing an electrical connection between said lamp end contact and the third terminal; said fourth terminal constituting an extension of said lamp casing tube and being slidably projected through a peripheral portion of said insulator means; said third and fourth terminals providing connections for an energizing circuit to said lamp.

^ 4. Inan illuminated push-button switch: a barrel having l means for attachment thereof to a support; an insulator sleeve lining said barrel; a lamp casing tube mounted for axially sliding movement in said sleeve, said tube having a projecting forward end provided with a push-button head having a light-transmitting window and having means for mounting an electric lamp therewithin; first, second, third and fourth terminals projecting axially from the rear endv of said barrel, said rst, second and third terminals each having at its forward end a part disposed in a radial plane, the second terminal part being disposed rearwardly of the first terminal part, insulator means secured in said rear end of the barrel and mounting said first, second and third terminals; a conductor pin slidable in said insulator means, said pin being electrically connected to said third terminal part and having its forward end in engagement with a central end contact of said lamp; means yieldingly urging said conductor pin and tube forwardly; a contact plunger mounted for axially sliding movement in said first terminal part near the inner wall of said sleeve; a

spring acting between said plunger and said first terminal c part to normally retract said plunger forwardly; insulator means for transmitting rearward movement from said tube to said plunger in response to pressure against said pushbutton head, whereby to effect rearward movement of said plunger, the latter being arranged, upon such rearward movement, to establish circuit-closing engagement with the second terminal part; said fourth terminal constituting an extension of said lamp casing tube and being slidably projected through a peripheral portion of said insulator means; said fourth and third terminals providing for con- 'D necting said lamp to a circuit for constantly energizing the lamp.

5. In an illuminated push-button switch: a barrel having means for attachment thereof to a support; a tube mounted for axially sliding movement in said barrel, said tube having a projecting forward end provided with a pushbutton head, and having means for mounting an electrical element therewithin; spring means normally retracting said tube forwardly; iirst, second, third and fourth terminals projecting axially from the rear end of said barrel, said rst and second terminals each having at its inner end a portion disposed in a radial plane, the second terminal end portion being disposed rearwardly of the first terminal end portion; a plurality of insulator discs secured in said rear end of the barrel and mounting the first, second and third terminals, said terminal end portions being arranged with said discs in a sandwich; means securing said discs and terminal end portions in said sandwich; means for establishing an electrical connection between the third terminal and one side of said electrical element; means providing a direct connection between the other side of said electrical element and said tube; the fourth terminal constituting an integral extension of the lateral wall of said tube, being slidably extended through peripheral areas of said discs, and having a radially inwardly projecting contact nger normally engaging said first terminal end portion on the rear side thereof with the retraction of said tube; a contact plunger mounted for axially sliding movement in said rst terminal end portion; a spring acting between said plunger and said first terminal ring to normally retract said plunger forwardly; insulator means for transmitting rearward movement from said tube to said plunger in response to pressure against said push-button head, whereby to effect rearward movement of said plunger, the latter being arranged, upon such rearward movement, to establish circuit closing engagement with said second terminal end portion.

6. In an illuminated push-button switch: a barrel having means for attachment thereof to a support; an insulator sleeve lining said barrel; a tube mounted for axially sliding movement in said sleeve, said tube having a projecting forward end provided with a push-button head having a light-transmitting window and having means for mounting an electric lamp therewithin; first, second, third and fourth terminals projecting axially from the rear end of said barrel; said first andv second terminals each having at its"` inner end a ring disposed in a radial plane, the second:

discs; a grommet extending through said discs and securing V the sandwich of discs and terminal rings together; means insulating said grommet from said rings; a conductor pin slidable in said grommet and having its forward end in engagement with a central end contact of said lamp;

means yieldingly urging said conductor pin forwardly to.

maintain said engagement; a contact plunger mounted for axially sliding movement in said first terminal ring at the periphery thereof; a spring acting between said plunger and said first terminal part to normally retract said plunger forwardly; insulator means for transmitting rearward movement from said tube to said plunger in response to pressure against said push-button head, whereby to effect rearward movement of said plunger, the latter being arranged, upon such rearward movement, to establish circuit-closing engagement with the second terminal ring, said conductor pin, grommet and spring establishing an electrical connection between said lamp end contact and the third terminal; said fourth terminal constituting an extension of said lamp casing tube, slidably projecting through peripheral portions of said insulator discs, and having a stop finger projecting radially inwardly between said insulator discs and normally engaging one of them for determining the forward limit position of said tube.

7. In an illuminated push-button switch: a barrel having means for attachment thereof to a support; a lamp casing tube mounted for axially sliding movement in said barrel, said tube having an end projecting from the forward end of said barrel and provided with a push-button head including a lens, and having means for mounting a lamp behind said lens; three terminals of L-form, each including an axially projecting terminal arm and a radially disposed v ring at the inner end thereof; a plurality of insulator discs sandwiched with said rings, said discs being secured in the rear end of said barrel and supporting said terminal arms; a grommet extending through the sandwich of discs and rings and securing them together; a conductor pin slidable in said grommet and having at its forward end a head for engagement with a central end contact of said lamp; a coil spring encircling said pin, engaged between said head thereof and said grommet, and yieldingly maintaining said end contact engagement; a contact plunger mounted for axially sliding movement in a first one of said terminal rings; a spring acting between said plunger and said first ring to normally retract said plunger forwardly; insulator means for transmitting rearward movement from said tube to said plunger in response to pressure against said push-button head, whereby to eifect rearward movement of said contact plunger, the latter being arranged, upon such rearward movement, to establish circuit-closing lengagement with a second one of said terminal rings, disposed rearwardly of said first ring; said conductor pin, grommet and spring establishing an electrical connection between said lamp end contact and the third terminal ring; and a fourth terminal arm constituting an extension of said lamp casing tube and slidably projecting through peripheral portions of said insulator discs, said fourth terminal arm having a contact projecting radially inwardly between said iirst and second terminal rings and normally engaging said irst terminal ring for normally closing another circuit.

8. In an illuminated push-button switch: a barrel having means for attachment thereof to a support; a lamp casing tube mounted for axially sliding movement in said barrel, said tube having an end projecting from the forward end of said barrel and provided with a push-button head including a lens, and having means for mounting a lamp behind said lens; first, second, third and fourth terminals projecting axially from the rear end of said barrel, said 

